I recently assembled the following combination of parts:
- Shimano 10-speed STIs (non-series, between 105 and Ultegra, ca. 2003)
- MicroShift 10-speed cassette (11-28)
- Tiagra 10-speed rear derailleur (Tiagra 4700-GS)
The problem is, either I set the tension low enough to reach the smallest cog in the back, but then shifting in the higher range isn't smooth and gears are skipped. Or I use higher tension, but then I can't reach the smallest cog and effectively run on a 9-speed.
It's like at some point, I have to go 2 clicks up or down to reach the next gear (somewhere in the middle of the range).
I tried with an old Ultegra (RD-6600) rear derailleur, but that couldn't reach all the gears. I remember from years ago, that a 12-27 cassette with that derailleur and the same lever wasn't a problem.
What am I missing here?